Effects of utilizing a granular nucleation layer on magnetic properties and microstructure of CoPt-B_2O_3 granular medium

摘要

The magnetic properties and microstructure of Co80Pt20-30 vol% B2O3 granular medium deposited on nucleation layers (NLs) with Co80Pt20-30 vol% oxides (oxides: Nb2O5, WO3, Ta2O5, SiO2, TiO2, Al2O3, Cr2O3, and ZrO2) of various thicknesses were investigated. By introducing an NL, a granular medium with columnar growth of small magnetic grains can be obtained. Furthermore, magnetic grains are separated with an oxide grain boundary material from the initial growth region that promotes the decoupling of magnetic grains, which corresponds to an increase in coercivity. The degrees of diameter reduction and decoupling of magnetic grains depend on the NL thickness and the melting point of the oxide utilized in the NL. (C) 2018 The Japan Society of Applied Physics